Hydraulic cylinder by-pass control



Feb. 22, 1944. H, R, ELUNWQOD Re. 22,439

HYDRAULIC CYLIDER BYPAss CONTROL Original Filed June 18. 1941 3 Sheets-Sheet l jyaf.

, W We 1 21036 a@ w D5 J E Fl'ab. 22, 1944. H R ELLlNwOoD Re. 22,439

HYDRAULIC CYLINDER BYPASS CONTROL Original Filed June 18. 1941 3 Sheets-Sheet 2 javaz Feb. 22, 1944. H. R. ELLlNwooD Re 22,439

A HYDRAULIC CYLINDER BYPASS CONTROL Original Filed Jun 18, 1941 3 Sheets-SheetA .'5

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Ressued Feb. 22, 1944 HYDRAULIC CYLINDER BY-PASS CONTROL Herman Ray Eilinwood, Burbank, Calif., assignor to Adel Precision Products Corp., a corporation of California Original No. 2,300,112, dated October 27, 1942, Se-

rial No. 398,621, June 18, 1941. Application for reissue January 1, 1944, Serial No, 516,699

'z claims. (o1. 121-40) My invention relates to valves for controlling the operation of hydraulic cylinders or jacks as used for operating as well as boosting the operation of airplane controls, for example, the diving brake flaps, rudders and the like, also other airplane mechanisms and devices which are subject to hydraulic operation and control.

It is the common practice to control the operation of hydraulic cylinders used in airplanes for the above' noted and analogous purposes, by,

means of 4-way valves which permit of selectively hydraulically extending and retracting the, pistons of the cylinders, but such valves do not make possible a manual or other external actuation of the cylinders and airplane controls connected therewith, nor provide-for hydraulically locking the controls or devices in predetermined positions, in a manner which has been found to be most essential to-an emcient operation of airplanes.

In consequence it is an object of my invention to provide a ilow control valve which is designed for use in combination with a 4way valve controlled hydraulic cylinder assembly, and adapted to be selectively operated as follows:

1. To lock or trap the iiuid in both ends of the cylinder and thereby hold the airplane control or device operated by the cylinder, in any position into which it is hydraulically or otherwise moved.

2. To permit the iluid to by-pass from one end of the cylinder to the other and thereby allow of free movement of the piston-in either direction and a manual or other operation of' the airplane control or device apart from hydraulic actuation of the piston.

`3. To allow of selective operation of .the cylinder under full control of the 4-way valve whereby the piston of the cylinder may be hydraulically extended or retracted. i

4. To achieve theY aforesaid hydraulic locking and by-passing operation at will and selectively regardless of the position of the i-way valve and thereby simplify, expedite and render more reliable the operation of controlling the hydraulic cylinder in accordance with this invention.

Another object of my invention is to provide a fluid control valve assembly of the character described in which six valve units are so constructed and so arranged in four bores within a small valve body of such form that appreciable and highly desirable reductions as to weight, size andmachiningcostsaswellastheuseofasimple form of means for selectively operating said valves. are afforded. Another obiect of my invention is to provide a new, and highly eiiicient 'hydraulic system -wherein two selectively operable valves make DOssible Aa full hydraulic operation, or a hydraulic boosting operation, or a full manual or other external operation of a member orydevice connected to the piston or plunger of the hydraulic cylinder, also a hydraulic locking of the piston or plunger in any position within the limits of its movement.

With the foregoing objects in View, together with such other objects and advantages as may subsequently appear, the invention is carried into effect as illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a vertical sectional view of a valve embodying my invention; taken on the plane l-I Fig, 2 is a perspective view of the valve shown in Fig. i; I

Fig. 3 is a sectional view taken on of Fig. 1;

Fig. 4 is a sectional view taken on the line 4 4 of Fig. 1;

Fig. 5 is a schematic view of a hydraulic system embodying my invention and including a 4-way valve and the valve of my invention with the latter in 1oclr'ing" position, the fluid being trapped in both ends of the cylinder and thereby locking piston against movement:

Fig. 6 is a fragmentary sectional view showing the position of the cam shaft and'valve stems when the valve assembly is in the position shown in Fis. 5;

the une' 3 3 Fig. '7 is a schematic view of the valve assembly as when in by-passing position in which the iluid will by-pass from one-end of the cylinder to the other to allow free movement of the piston in either direction; 1

Fig. 8 is a fragmentary sectional view of the cam shaft and valve stems as when the valve assembly is in by-passing position shown in Fig. .'t;

Fig. 9 is a schematic view of the valve assembly as when in free ilow position in which the' cylinder is controlled solely by the i-way valve to hydraulically extend and retract the piston;

Fig. 10 is a fragmentary sectional view of the cam shaft and valve stems as when thevalve is in free flow position shown' in Fig. 9v.-

Referring to the drawings' more specifically, Figs. 1 to 4 inclusive show a valve assembly em- Y bodying'my invention and which generally includes a body I having valve hores 2, 3, l, and l.

poppet valves 2a and 2b in the bore 2, poppet valves la and lb in the bore I, and pcppet valves la and 5a in the bores land l respectively.

single rotary cam shaft B mounted in a bore 1 in the body I provides for operating the aforesaid poppet valves as will `be hereinafter more fully described, said cam shaft being of such form that the bore 8 serves as a fluidpassageway between the inner ends of the bores 2 and 3. cam shaft is movable into three positions as indicated by the characters 1, 2, and 3 spaced 90 degrees apart on a disk 8 at one end of the body I, said three positions determining the hydraulic locking, the by-passing and the free flow 4-way valve control positions of the valveas respectively illustrated in Figs. 5, '1, and 9 as to the valve and in Figs. 6, 8 and 10 as to the cam shaft and associated parts. The cam shaft may be rotated by any suitable means, not shown. Threaded into the outer ends of the bores 2, 3. 4 and 5 are fittings III, Il, I2 and I3 respectively for connecting the valve in a hydraulic system.

One hydraulic system embodying my invention is shown in Fig. and includes a hydraulic cyl-- inder A, a piston B in said cylinder. adapted to be connected to `an airplane control 0r device, not shown, a ,4-way valve C, pressure and return lines D `and E leading froml a hydraulic pump unit, not shown, to the 4-way valve, a' relief bypass valve- R in a by-passline S around the `1 valve C, fluid lines F and G leading from the 4- way valve to the fittings. Ili and I I of a valve assembly H embodying my invention, and fluid lines F' and 'G' leading from the fittings I2 and I3 of said valve assembly to the opposite ends of the cylinder A.

Before describing the operation of the system shown schematically in Figs. 5, 'I and 9, the construction of the valve assembly H will be described.

With reference to Figs. l to 4` inclusive, it is seen that the bores 2 and 3 are extended froml in Fig. 3. A suitable sealing means IB for saidV shaft is mounted in a recess I3 in the end face I1. Thus in effect the valve bores 2 and lform -an L-shaped valve chamber whereas the valve bores 3 and 5 forma similar valve chamber, the

cam shaft bore intersecting the junctures of valve boresand the two L-shaped chambers being in spaced parallel relation to Vone another.

Removably seated in the bore 2 is a cylindrical seat member 20 having a reduced inner portion 2| and a beveled annular shoulder 22 which latter seats .on a beveled shoulder 23 intermediate the ends of said bore. Sealing rings 24 are seated in a shoulder 25 on the member 20 and lie between said member and the wall of the bore 2, .being held in place by means of the inner end of the fitting Il contacting with Vthe outermost sealing ringas shown in Figs. l and 3. It is now seen,

that'member 2liv serves asa partition means dividing the inner end and outer portion of the bore and provides `for connection thereof only through its'bore.

2IIl and is Aheld seatedby means of a spring 21 -engaged between the valve and an`annu1ar shoull der 23 in the fitting I0.

A valve-seat 29 for the valve 2b is formed between the ends of and withinv the bore of the The valve 2a,is adapted to engage a seat2l on the outer ,end of the member cylindrical seat member 20. The valve 2b is-tubular and the stem 30 of the valve 2a is slidable in the bore of and extends beyond the tubular` in a recess 33 in the outer end of thevalve 2b 34 of less tension than spring 21 holds the valve 2b seated and also holds the ring 32 in place.

In the seat member 20 above the seat 29 are radial ports 35 opening into an annular enlargement or recess 36 in the bore 2. VA passage 31 in the body I connects the enlargement 3i with a similar enlargement 38 in the bore 4 for the valve 4a. v

The tubular valve 2b is reduced between its ends to define an annular chamber 39 within the reduced 'part 2| of the member 20 which chamber is at all times in communication with the inner end of the bore tand cam shaft bore 1 by means of radial ports 40 in the portion 2|, whereby the cam shaft bore will serve as aconnecting passage between the inner ends of the valve bores 2 and` 3 for lay-passing the fluid as indicated in Fig. 7 and as will be hereinafter described.

Mounted in the valve bore 4 is a cylindrical valve seat member 3| having an end wall 42 closend of said bore, there being cooperating beveled shoulders 43 and 44 on the wall of the bore 4 and exterior of the member 4| respectively. The inner end of the fitting I2 engages sealing rings 45 corresponding to the rings 24 and holds the mem-` ber 4| in place with its radial ports 56 in registration with the enlargement 38 of bore 4.

Atits outer end the member 4| has anannularseat 41 for the valve 4a which latter is normally seated by means of a spring 48 arranged as is the spring 21. The stem 43 of the valve 4a extends through the Wall 42 for contact with Y the cam shaft l, there being a sealing means 49' identical with the sealing means 32 and held in a recess SII'in the wall 42 by means of a spring l5 I.

As the valves l3a and 3b and associated ports in the bore 3 are identical with the valves 2a and 2b respectively and their associated parts, and as the valve 5a and associated parts are identical with valve 4a and its associated parts, the same reference characters are used to designate such like parts throughout the drawings and specifications hereof. A e

The camshaft 6 is provided with cams 52 and 53 set alike for simultaneously engaging the stems 30 of the valves 2a and 3a and opening said valves as shown in Figs; 9 and 10, when the cam shaft is turned to free ilow position permitting full control of the hydraulic cylinder through the 4- way valve C. When the shaft -is in this position vcams 54 and. thereon also simultaneously engage the stems 43 the valves 4a and 5a and open said valves as also shown in Figs. 9 and 10. `The cams 54 and 55 also adapted to simultaneously engage the stems 49 of and'open thevalves 4a and lia when the cam shaft is turned toV bye pass position, as shown in Figs."1 and 8. Cams- 53 and B1 on the shaft 8 are set to engage the stems 3| of valves 2b and 3b' and open said valves only when the shaft is turned to by-pass position as shown in Figs. 'l' and 8. Figs. 6, 8 and 10 show the cam shaft cams and valve stems when the valves are in the positions shown in Figs. 5, 'l and 9 respectively, said valvemositions ybeing respectively the fluid locking position, the by-passI- f valves Ib vand ing position. and the free flow position in which the cylinder is under full control of the i-way valve C.

It should be noted that the body I may be conveniently made from bar stock and comparatively inexpensively provided with the necessary bores and passages for accommodating six valves in four bores whereby to render the assembly more compact and appreciably reduce the size and weight thereof. Moreover, the construction of the cylindrical seat members and valves and their relative arrangement makes possible a reand cam shaft bore I which completes the bypass circuit. As the piston has equal areas on opposite sides thereof the uid displaced by the piston from either end of the cylinder is accommodated in the other end of the cylinder.

As the valves 2a and 3a are closed when this by-passing operation takes place, the fluid cans duction in machining costs compared to valves in which the seats and associated ports and cham-v bers are machined in the Abody itself. this construction makes for a quick and accurate assembling and disassembling of the valve and f seat elements to facilitate repair and replacementV of parts.

Referring again to the hydraulic system shown in Figs. 5, '1,' and 9, it is seen that when it is desired to lock an airplane control or device (not shown) and which is connected with the piston B, in any position Iinto which it may have been moved hydraulically or by a manual or other means independent of hydraulic actuation of the piston, the operator merely moves the cam shaft I of the valve assembly Hinto position shown in Fig. 6 whereby the DOPPet valves in said assemply will close as shown in Fig. 5. Closing of poppet valves 2a and 3a will shut off the pressure iluid to the valve H and cylinder A, and closing of poppet valves la -and la will trap the fluid in the cylinder A on opposite sides of the piston B and thereby lock the piston. Should the 4-way valve be in the position shown in Fig. 5 when the POPDet valves are closed as aforesaid, lthe pressure iluid will circulate freely .through pressure line D,-port 60 in valve C, and return line E. Inasmuch as in systems such as here shown the hydraulic pump, not shown, is operated continuously, it isnoted that should the valve C be in other than the position shown in Fig. 5 pressure increase caused by the closed valves laand la will open lthe pressure relief valve R in the bypass line S whereby the pressure iluid will bypass around the valve C into the return line E.

not flow back into lines F and G. Moreover,

inasmuch as valves la and 3a are closed atthis time, it is seen that the by-passing operation of valve H is in no way dependent on a particular position of the 4-way valve. The relief valve R will open and allow pressure iluid toI by-pass around the valve C if the latter is in a position other than shown in Fig. 5.

When it is desired to operate the cylinder A with the 4way valve C to hydraulically extend or retract the piston B, the cam shaft l of the valve assembly H is turned .to position shown in Fig. 10 and the valves 2a, 8a, la and 5a are opened, whereas llay-pass valves 2b and 3b are closed, and the valve C is then manipulated'to bring its ports t2 and il into registration with the pressure and yreturn lines D and E and the lines F and G.

Assuming the valve is operated so that port l! establishes a connection between lines D and F as the pressure line to valve H, and port 63 establishes connection between lines G and E as the fiuid return line, then the pressure fluid is edective in the iltting I0,l cylindrical seat member 20 for the then open valve Imports 35, enlargement IB of bore 2, passage S1, enlargement 'Il of bore l for then open valve la, ports 4B,

seat member 4I, fitting I2, line Fand the left end oi' the cylinder A. 'I'he piston is now movedto the right or extended, while the fluid in the 1 right end of the cylinder returns through line- G', fitting II, seat member ll iti-.bore i, past open valve'la, ports Il, passage 31 to port 3. ports 35,'seat' member 21| in bore 3, past open valve la, through fitting Il and vline G. valve port l! to return line E at valve C. 'It is obvious from the foregoing that when the valve 6 is turned to communicate its port 63 with the lines l D and G and its port B2 with the lines E and F This pressure relief check valve is set to open .is now apparent that the fluid locking operation of the valve H is in no way dependent on the. 4-way valve C as to the latter` being set or moved the 'piston will be retracted.

It is important to note that the valve means and the system embodying my invention make possible the operation and control of airplane controls or airplane carried devices in such inanner as to permit of a most efilcient operation of airplanes with greater facility and safety due to ythe fact that said controls or devices may be selectively manually operated, hydraulically oper-- into any particular position and this is important u ated, and operated by means other than the hyas it insures a quicker, easier and more positive fluid lockingand-releaslng-operation. V Y

When it is desired to release the piston B for` free movement in either direction to permitoi operation of the airplane control device manually or by means other than a hydraulic actuation ofthe plato the cam shaft i is turned to the position shown in Fig. 8 andthe bypass 3b, also the valves la and Icare simultaneously opened as shown in Fig. 7. When the piston is now moved in either direction by external means as aforesaid, fluid will by-pass from one end of the cylinder to the other around the piston as' follows: through the linesv F' and G', fittings I! andV Il. bores l and. l.' open valves Iaand la, passages 31, enlargements 3l in bores I and I, ports 8l in cylindrical seat members Il. .past the open valves Ib andjb, through the reduced portions 2| of members Il, ports Il in said reduced portions, inner ends of bores I and I.

y formation and -arrangement as come within the purview of the appended claims.

I claim: l 1. In a hydraulic control valve, a body having a plurality of valve receiving bores opening on outer faces thereof and a cam shaft receiving bore. valve seats axially spaced apart 'between the ends of each valve receiving -bore of a. pair thereof. inwardly seating axially -spaced poppet valves in each bore of said pair having stems extending into said cam shaft receiving bore, a'. valve seatvdisposed between the ends of eachj,l

seats therein and its other terminal communicated with a bore of said second named pair at a point spaced inwardly of the valve seat in the latter, another fluid passage having one terminal communicated with the other bore of the rst named pair at a point between the valve seats therein and its other terminal communicated with the other bore of the second named pair at a point'inwardly of the valve seat in the lat ter, the inner ends of the valve bores of the first named pair opening into said cam shaft bore which serves as a fluid passage between said inner ends, and a cam shaft operable in the bore therefor for controlling said valves.

#2.In a hydraulic control valve, a body having a plurality of valve' receiving bores opening on outer faces thereof and a cam shaft receiving bore, valve seats' axially spaced apart between the ends of each valve receiving bore of a pair thereof,4 inwardly seating axially spaced poppet valves in each bore of said pair having stems extending into said cam shaft receiving bore, a

. valve seat disposed between the ends of each bore of another pair of said valve receiving bores, an inwardly seating poppet valve in each bore of said second named pair having a stem extending into said cam shaft receiving bore. means affording the communication of each valve receiving bore at a point between its outer end and the next adjacent valve seat therein with a iiuid line, a fluid passage in the body having one terminal communicated with a b`ore of said rst named .pair at a point between the valve seats therein and its other terminal communicated with a bore of said second named pair atapointspaced inwardly of the valve seat in the latter, another fluid passage having one terminal communicated with the other bore of the first named pair at a ypoint between the valve seats therein and its to bores of the first namedpair in the plane of the latter. Y e

3. In a hydraulic control valve, a body having a plurality of valve receiving'bores opening on `outer facesthereof and {cam-'shaft receiving vsansa cent valve seat therein with a 'uid line, a fluid passage in the body having one terminal communicated with a bore of said iirst named 'pair at a point between the valve seats therein and ,its other terminal communicated with a bore of said second named pair at a point spaced lnwardly of the valve seat in the latter, another iiuid passage having one terminal communicated with the other bore of the first named pair at a point between the valve seats therein and its other terminal communicated with the other bore of the second named pair at a point inwardly of the valve seat in the latter, the inner ends of the valve bores of the first named pair opening into said cam shaft bore which serves as a fluid passage between said inner ends, and a cam shaft operable in the bore therefor for controlling said valves, tubular` valve seat members in the bores of the second named pair having the aforesaid valve seats on their outer ends and provided with means on their inner ends for sealing the inner ends of the second named pair of bores.

4i In a hydraulic control valve,'a body having a plurality of valve receiving bores opening on outer faces thereof and a cam shaft receiving bore, valve seats axially spaced apart between the ends of each valve receiving bore of a pair thereof, inwardly seating axilially spaced poppet valves in each bore of said pair having stems extending into said cam shaft receiving bore, a valve seat disposed between the ends of each bore of another pair of said valve receiving bores, an inwardly seating poppet valve in each bore of said second'named pair having a stem extending into said cam shaft receiving bore, means affording the communication of each valve receiving bore at a pointbetween its outer end and the next adjacent valve seat therein with a'lluid line, a fluid passage in the body having one terminal communicated with a bore of said iirst named pair at a point between the valve seats therein and its other terminal communicated with a bore of said second named pair at a point spaced inwardly of the valve seat in the latter, another fluid passage'having one terminal communicated with the other bore of the rst named pair at a point between the valve seats therein and its other terminal communicated with the other bore of the second named pair at a point inwardly of the valve seat in the latter, the inner ends of the valve bores of the first named pair opening into said cam shaft bore which serves as a fluid passage between said inner ends, and a cam shaft operable-in the bore therefore for controlling said valves, tubular valve seat members seated in the valve receiving bores for providing the bore, valve seats axially spaced apartbetween the s r ends of each valve receiving bore of a pair thereof, inwardly seating axially spaced poppet valves in each bore of said pair having stemsl extending into said cam shaft receiving bore, a valve seat disposed between the ends of each bore of another pair of said valve receivingv bores, an inwardly seating poppet valve in each bore of said second aforesaid valve seats, andA ttlngs extending into said bores and holding said seat members therein.

5. In a hydraulic control valve, a body having a plurality of valve receiving bores opening on fouter faces thereof and a cam` shaft receiving bore, valve seats axially spaced apart between the ends of each` valve receivingl bore of a pair thereof, inwardly seating axially spaced poppet valves in each bore of said pair having stems. extending intosaid cam shaft receiving, bore,- `a

i valve seat disposed between the ends of each bore named pair having a stem extending into said cam shaft receiving bore, means affording the communication of each valve receiving bore at of another pair of. said valve receiving bores, an

,inwardly seating poppet' valve in each bore )of .said secondnam'edpair having a stem extending into said cani shaft receiving bore, means affording the communicationwof each valve `receiving y bore ata pointbetween itsouter `endrgand the next adjacent `valve v,seat therein with a;

vwww M l n 5.

une, a Vuuid 'e in the body having one terminal communicated with a bore oi' said ilrst named pair at`a point between the valve seats therein and its other, terminal communicated with a bore of said second named pair at a point spaced inwardly of the valve seat in the latter, another iluid passage having one terminal communicated with the other bore oi.' the ilrst named pair at a ,point between the valve seats therein and its other terminal communicated with the other bore of the second named pair at a point inwardly I the valve 'seat in the latter, the inner ends of the valve bores or the rst named pair opening into said cam shaft bore which serves as a luid passage between said inner ends, and a cam shaft operable in the bore therefor for controlling .said valves, tubular valve y seat members seated in the valve receiving bores for providing tht I -:esaid valve seats, andfttings extending into said bores and holding said seat members therein, said tubular seat members having ports for registration with said'passages.

6. In a iiuid control valve, a body having a 5 cam shaft bore and a pair .of valve receiving Abores extending radially from'the cam shaft bore and opening through outer' fa'ces 'of the'body, a

pair of valve seats axially spaced apart in one of the valve receiving bores, a pair of poppet valves arranged to seat inwardly against said seats, concentricstems on said valves extending into said cam shaft bore, a valve seat in the other valve receiving bore, a poppet valve arranged to seat inwardlyv against the seat in the second named valve bore, means embodied in -the body for communicating the portions oi the valve boresA between their outer ends .and'the next adjacent valves therein with iluid lines, a iiuid passage in the body having one terminal communicated with a point in the 'Iirst named valve bore between the valve seats therein, and its' other terminal communicated with the .second named valve bore a pair of valve seats axially spaced apart in one. '-1

ci the valve receiving' bores, a pair of poppet?y valves arranged to seat inwardly against said'- seats, concentric stems on said valves extending g l at a point inwardly spaced from the seat in the latter, and a camshaft operable in the bore therefor to selectively operateL said valves.

7.-In a uid control valve, a bodv having a cam shaft bore and a pair ofv valve receiving bores extending radially from the camshaft bore and opening through outer faces oi the body.

intosaid cam shaft bore, a valve seat in the other valve receiving bore, a poppet valve arranged to seat inwardly against the seat in the secondv named valve bore, means embodied in lthe body latter, and a cam shaft operable in the boretherefor to selectively operate said valves, a cylindrical seat memberin the first named valve bore having the valve seats for said bore located at its outer end and between its ends respectively and provided with ports inwardly spaced from the respective seats, a cylindrical seat member in the .second namedyvalve bore having the lvalve seat for said bore on its outer end' and provided with a port spaced inwardly of said seat and a wall at its inner end closing the inner vend of a second named bore, ttings in the outer ends of the valve bores engaging and holding said seat members in place, springs between said fittings and l valves in said' bores for seating such valves, and a spring between the valves in the ilrst named bore for seating the inner valve oi said pair.

HERMAN RAY ELIINWOOD. 

